Long-term results of laser in situ keratomileusis for high myopia: risk for ectasia.

PURPOSE: To ascertain the long-term stability of laser in situ keratomileusis (LASIK) in highly myopic eyes. SETTING: Clinical practice office-based surgery. METHOD: Charts of eyes with high myopia who had LASIK surgery by the same surgeon between 1994 and 2000 were reviewed in 2003, and patients were given an appointment for follow-up examinations. In these highly myopic eyes, surgery was originally performed to create undercorrections with or without decreasing the ablation diameters to maximally conserve the residual stromal bed thickness. RESULTS: Of the 107 eyes with myopia between -10.00 diopters (D) and -35.00 D reviewed and operated on in a 3-year period between 1994 and 1998, 35 eyes of 31 patients had a single enhancement procedure. One case of ectasia as a result of excessive tissue removal occurred in a patient with a preoperative refraction of -28.00 D. Of the 107 eyes reviewed, 78 (73%) were examined after 5 years, 68 (63%) after 7 years, and 15 (14%) between 9 years and 11 years. CONCLUSIONS: Operating on eyes with highly myopic refractive errors and removing substantial tissue thickness did not produce ectasia in this series. Although high myopia has been considered a risk factor for post-LASIK ectasia, adherence to proper screening and intraoperative pachymetry appears to decrease the risk.

2005 ESCRS Ridley Medal Lecture: will keratectasia be a major complication for LASIK in the long term?

The literature on keratoconus and progressive post-laser in situ keratomileusis ectasia (PPLK) was studied after a retrospective review of 137 highly myopic eyes (mean -15.58 diopters) 5 to 9 years after LASIK. Only 2 eyes developed keratectasia, 1 after automated lamellar keratolasty for myopia and 1 after myopic LASIK. In neither case was intraoperative pachymetry carried out. In the PPLK case, a residual stromal bed thickness (RSBT) of 120 microm was discovered when a retreatment was attempted on lifting the flap. The PPLK developed 2 years later. The obvious discrepancy between reported cases of PPLK and the expected rate from the incidences in larger retrospective studies and our own 15-year experience suggests that PPLK is not a significant complication provided the standard rules applying to the preoperative total corneal thickness and RSBT are observed. However, newer techniques for the study of posterior corneal changes and those involving corneal biomechanics should be used in the future to study the long-term effects of LASIK on the cornea.

Twelve-year follow-up of photorefractive keratectomy for low to moderate myopia.

PURPOSE: To evaluate long-term safety and stability in a group of myopic patients who underwent photorefractive keratectomy (PRK) > or =12 years ago. METHODS: Myopic PRK was performed on 120 eyes of 80 patients using the Summit UV200 excimer laser with a 5-mm ablation zone. Of the original group, most of whom were followed for > or =2 years (mean 2.6 +/- 1.7 years), 34 patients (58 eyes) returned at 12 years (mean 12.7 +/- 0.79 years) and had refractive stability, refractive predictability, best spectacle-corrected visual acuity (BSCVA), corneal haze, and subjective patient symptoms, such as glare/halos, recorded. RESULTS: Preoperative mean refractive spherical equivalent (MRSE) ranged from -1.75 to -7.25 diopters (D) and astigmatism from 0.00 to 1.50 D. All eyes underwent a change in manifest refraction over 12 years. At 2 years, MRSE was -0.27 +/- 0.55 D and at 12 years was -0.58 +/- 0.72 D. In 87.9% of eyes, the level of preoperative BSCVA was maintained or improved, whereas 34.5% of eyes gained one line, and 12.1% lost one line of BSCVA. Uncorrected visual acuity > or = 20/20 was noted in 67% of eyes, whereas 62.1% were within +/- 0.50 D of emmetropia. Trace haze was noted in 17.2% of eyes at 12 years. One patient had a rhegmatogenous retinal detachment, but this was unlikely due to the PRK procedure. With respect to the small optical zone, 14 (41.1%) patients had night visual problems, particularly halos, which were severe in 2.7%. All patients questioned stated they would have the procedure done again. CONCLUSIONS: Photorefractive keratectomy with the Summit UV200 excimer laser effectively reduced myopia and showed good refractive stability from year 2 to 12 with good patient satisfaction.

Meningococcal septicemia presenting as bilateral endophthalmitis.

We present a patient with bilateral endophthalmitis as the presenting sign of meningococcal septicemia. Systematic examination and vitreous tap conclusively identified the microbe, and appropriate treatment was administered, with good recovery of vision.

Recurrent visual loss in homozygous sickle cell disease

In sickle cell retinopathy vascular involvement is most frequently recognised at the retinal periphery but obstruction of perimacular arterioles and of major retinal vessels may also occur. This report describes a patient with homozygous sickle cell (SS) disease with recurrent occlusion of major retinal vessels associated with recurring transient impairment of visual function. (Summary)

A randomized clinical trial of feeder vessel photocoagulation of proliferative sickle cell retinopathy. I. Preliminary results

A randomized prospective clinical trial of feeder vessel photocoagulation for proliferative sickle cell retinopathy was performed. In Chicago, there were 34 argon laser-treated eyes and 30 control eyes. In Kingston, there were 53 xenon arc treated eyes and 50 control eyes. Prolonged loss of visual acuity was rare in both photocoagulated and control eyes. Argon laser and xenon arc feeder vessel photocoagulation reduced the incidence of vitreous hemorrhage and visual loss from vitreous hemorrhage. However, photocoagulation was associated with an increased risk of choroidal neovascularization (xenon arc greater than argon laser) and retinal detachment (argon laser), although visual loss from these complications has not been in these patients so far. (AU)

Central retinal artery occlusion without retrobulbar hemorrhage after retrobulbar anaesthesia

Four patients had central retinal artery occlusions after retrobulbar anaesthesia with lidocaine HCl was administered before photocoagulation. One of these four had two separate episodes of closure. Only one had permanent visual loss and none had evidence of retrobulbar hemorrhage. Each patient had a severe hematologic or vascular disorder. We think that direct trauma to the central retinal artery behind the globe, the pharmacologic or compressive effects of the injected solution,or both caused the occlusions in these patients. (AU)

Haematological factors associated with proliferative retinopathy in sickle cell-haemoglobin C disease

In a selected sample of patients with sickle cell-haemoglobin C (SC) disease, proliferative retinopathy (PSR) occurred in 90/243 (37 percent) patients, developed most frequently between the ages of 20 and 30 years, and affected 68 percent patients aged 45 years or over. Comparison of haematological indices in patients with and without PSR, after age-related effects were allowed for, indicated significant relationships with high mean cell volume in males and with low fetal haemoglobin in both sexes. A highly significant relationship with total haemoglobin level in males (as previously reported in SS disease) was shown in SC disease to be entirely secondary to a strong age-related trend in haemoglobin level (AU)

Angioid streaks in Jamaican patients with homozygous sickle cell disease

Angioid streaks were observed in 21 of 242 patients with homozygous sickle cell disease. Two morphological types were observed. There is no evidence that angioid streaks in Jamaican patients are related to pseudoxanthoma elasticum (AU)

Choroidal neovascularisation induced by photocoagulation in sickle cell disease

Choroidal neovascularisation occurred in 35 out of 57 (61 percent) patients during a trial of xenon arc photocoagulation in proliferative sickle retinopathy. Nineteen patients manifested abnormal vessel systems in the plane of the retina which tended to be benign, not enlarging and without complications (choroidoretinal neovascularization). In 16 patients the abnormal vessel system grew into the vitreous, tended to increase in size and to be associated with vitreous haemorrhage and retinal traction (choroidovitreal neovascularisation). Both forms of neovascularisation were significantly more common at younger ages. Treatment was generally unsatisfactory, frequently resulting in further enlargement of the lesions. Although the natural history of choroidal neovascularisation and its ultimate effect on visual function remains to be recorded, these lesions constitute a common and potentially serious complication of xenon arc photocoagulation in proliferative sickle retinopathy as currently performed. (Summary)

Salmon-patch hemorrhages after central retinal artery occlusion in sickle cell disease

In two patients with sickle cell disease (one hemoglobin SC and one hemoglobin SS), central retinal artery occlusion developed. In one case, the occlusion followed a retrobular injection of lidocaine hydrochloride. Although the central retinal artery reperfused in each patient, many secondary peripheral retinal ateriolar occlusions remained. During the subsequent days, multiple salmon-patch hemorrhages developed in the distribution of these occluded arterioles. In one patient, the salmon-patch hemorrhages evolved into atrophic schisis cavities. These unusual cases allowed us to document the origin of salmon-patch hemorrhages after peripheral retinal arteriolar occlusions. The development of the hemorrhages was a delayed phenomenon that occurred hours to days after the initial vascular occlusion. Reperfusion of the damaged ischemic vessels with a blowout of the walls of the vessels seems the most likely explanation for this phenomenon. (Au)

Haematological factors associated with proliferative retinopathy in homozygous sickle cell disease

Haematological indices were investigated in 261 patients with homozygous sickle cell disease, 29 of whom had developed proliferative sickle retinopathy (PSR). After allowing for age-related effects, male patients with high Hb (>9 g/dl) and low HbF (<5 ) percent levels appeared to constitute a high risk group for PSR. This relationaship was not evident in females, PSR being observed in patients with lower Hb and higher HbF levels than in the male group. PSR occurred in 14 percent of patients aged 40 years or over in this sample (AU)

Retinal and choroidal neovascularization in sickle cell disease.

Small vessel obstruction characterizes sickle cell disease and when occurring in the peripheral retinal vessels, initiates a sequence of vascular events which may culminate in the development of proliferative sickle retinopathy (PSR). Repeated examinations of the retinal vasculature of patients with different genotypes of sickle cell disease over the last 10 years (Condon and Serjeant,1972a,b,c; 1975; 1980a) have allowed observations on the natural history of PSR and on factors related to its development. Choroidal neovascularization has been a common complication of a trial of xenon arc photo-coagulation in PSR. Observations on the aetiology and natural history of both retinal and choroidal neovascularization are presented in this report. (AU)

Behaviour of untreated proliferative sickle retinopathy

The development of ocular lesions in 313 patients with sickle cell disease followed up for periods of 1-8 years is described. Proliferative sickle retinopathy (PSR) was present on initial examination in 68 (12 percent) of 567 eyes and developed in a further 46 (8 percent) eyes during the study period. Spontaneous regression (autoinfarction) was present on initial examination in 33 (49 percent) eyes with PSR initially and developed in a further 45 (39 percent) eyes during the study. Development of PSR was common in sickle cell-hemoglobin C (SC) disease, and autoinfarction appeared to occur more commonly in homozygous sickle cell (SS) disease. The two processes were delicately balanced, and some PSR lesions lasted less than a year before undergoing autoinfarction. Although the high prevalence of autoinfartion diminishes the clinical sequelae of PSR, blindness related to PSR occurred in 14/119 (12 percent) eyes. Autoinfarction closes the feeding vessels of PSR lesions more elegantly than, and without the complications associated with, photocoagulation. A greater understanding of factors involved in the progression and regression of PSR is relevant to defining the role of photocoagulation in this condition. (Summary)

Ocular findings in sickle cell-haemoglobin O Arab disease

The ocular findings in 2 patients with sickle cell-haemoglobin O Arab disease are described. One patient had proliferative sickle cell retinopathy with extensive autoinfarction of lesions. Sickle cell-haemoglobin O Arab disease must be added to the list of conditions that may be associated with proliferative sickle cell retinopathy (AU)

Ocular findings in elderly cases of homozygous sickle-cell disease in Jamaica

The ocular findings in 60 patients with homozygous sickle-cell disease over the age of 40 years have been described. Peripheral retinal vessel disease was common and appeared to increase with age. Retinitis proliferans was common among older patients in the group. Angioid streaks occurred in 13 (22 percent) patients. (Summary)

Photocoagulation and diathermy in the treatment of proliferative sickle retinopathy

The O'Malley Log II portable photocoagulator was used to treat the worse eye of 36 patients with proliferative sickle cell retinopathy flat on the retinal surface. The technique involved direct coagulation of the feeder arterioles before treatment of the new vessels themselves. The photocoagulator was most successful in treating the lesions and 131 of 137 retinitis proliferans (RP) lesions were occluded. In only one RP lesion did the photocoagulator have insufficient power to occlude the lesion. Vitreous haemorrhage occurred in only one patient and small round localized retinal haemorrhages in five. The Manchester portable diathermy machine successfully occluded all 29 raised RP lesions and fifty feeder arterioles in thirteen patients. Anterior segment ischaemia occurred in only one patient who had advanced traction retinopathy involving 360 degrees of arc of the retinal circumference before treatment. No recurrence of retinopathy over a 2-year follow-up period was seen in seven patients and in the remainder there was no recurrence in the 2 months after treatment. (Summary)

Ocular findings in children with sickle cell haemoglobin C disease in Jamaica

The ophthalmological findings in 54 Jamaican children with SC disease are reported. Evidence of peripheral retinal vessel disease was present in 94 percent and retinitis proliferans in 11 percent. Retinitis proliferans was noted as early as 7 years of age and was more common in patients with high haemoglobin levels. There was an unequivocal progression in severity of retinopathy in eight out of eleven children examined 2 years previously. The pathological processes leading to sickle cell proliferative retinopathy are well established in childhood and attempts at prophylactic therapy should be instituted at an early age. (Summary)